Aim: To review selectively the status of the genetic research in the field of speech and language disorders.
Development: Major contributions to the field are selected, presented, and discussed. Twin and family studies have demonstrated that most cognitive traits including language are moderately to highly heritable. Rare mutations affecting the FOXP2 transcription factor cause a monogenic speech and language disorder. The results of association studies of FOXP2 with several language disorders are controversial, probably due to the problem of phenotype definition.
Conclusions: Common forms of disorders of speech and language are mostly likely associated with variability in the function of multiple genes. Longitudinal studies looking at gene environmental interaction might be important in order to understand the mechanism of language development.